21091819373 has 8 divisors (see below), whose sum is σ = 21236018496. Its totient is φ = 20947680000.

The previous prime is 21091819367. The next prime is 21091819417. The reversal of 21091819373 is 37391819012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21091819373 - 2²⁰ = 21090770797 is a prime.

It is a super-2 number, since 2×21091819373² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21091819313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 871565 + ... + 895437.

It is an arithmetic number, because the mean of its divisors is an integer number (2654502312).

Almost surely, 2^21091819373 is an apocalyptic number.

It is an amenable number.

21091819373 is a deficient number, since it is larger than the sum of its proper divisors (144199123).

21091819373 is a wasteful number, since it uses less digits than its factorization.

21091819373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29875.

The product of its (nonzero) digits is 81648, while the sum is 44.

The spelling of 21091819373 in words is "twenty-one billion, ninety-one million, eight hundred nineteen thousand, three hundred seventy-three".